The present invention relates to rotary members and methods and apparatus for forming such members from sheet metal.
It is known to provide rotary members such as wheels, pulleys, clutch discs and the like, having an integral hub formed from sheet metal stock. It is also known to provide V-groove pulleys and the like, formed from a sheet metal blank by splitting the blank edgewise to form the walls of the groove.
According to the prior art, the articles have a wall thickness equal to or less than the thickness of the stock from which it is made. For example, where an integral hub is formed by drawing, the wall thickness of the hub may be thinner than the blank from which it is made. Where a disc is split to form a V-groove, the thickness of each wall is generally half or less than half the thickness of the stock from which it is made. Thus the stock from which the article is made must be selected to provide the desired thickness in the thinnest section of the finished article.